1. Field of the Invention
The present invention relates generally to row finding devices and more specifically to a row finder probe for use with automatic steering systems for cotton harvesters and the like.
2. Related Art
To help an operator of agricultural row crop equipment maintain proper alignment of machinery with the rows, numerous row finding devices have been employed. These devices, which help to reduce operator fatigue and increase machine productivity, often include a probe or feeler for contacting a row of the crop and providing a signal responsive to relative movement of the equipment and row from an optimal position. The signal is utilized to provide a steering change to move the equipment toward the desired optimal position relative to the row. Recently, such devices have been made commercially available for automatically guiding a cotton harvester. An example of a cotton harvest guidance system is the Orthman.RTM. CSC Harvester Guidance, available from Orthman Manufacturing, Inc. of Lexington, Nebr. Steering is controlled automatically by a hydraulic control module operably connected to the hydraulic steering cylinder. A pendulum probe is connected to the harvester row unit for rocking about a generally fore-and-aft extending axis and includes feelers that extend along opposite sides of the lower portions of the cotton plants in one of the rows of cotton being harvested. If the row unit moves off center from the desired position the pendulum pivots to change the setting on a potentiometer. A microprocessor responsive to the potentiometer setting is connected to the hydraulic control module which, using a proportional valve, operates the steering cylinder to make the necessary correction to move the row unit back to a centered position.
One problem that has surfaced with respect to the pendulum type feeler system on a cotton picker row unit is susceptibility to clogging which renders the system inoperative. The feelers must be located very close to the base of the cotton plants for proper pendulum action. Stalk lifters are also located near the bottom of the row units, and clumps of debris frequently lodge between one of the feelers and the corresponding lifter. The feelers also diverge outwardly in the forward direction to facilitate receipt of the bases of the cotton plants, and the outwardly diverging portions terminate at locations offset from the side of the row unit throat area so that debris catches easily and renders the system inoperative.